Sex Disparity in Outcomes of Total Joint Arthroplasty?

Women May Be More Hypersensitive to Metal Components of Joint Replacement Then Men

Findings from a study conducted by a team from Rush University Medical Center, Chicago may help to explain the higher incidence of complications from total hip and knee replacement surgery in women as compared to men. The study implicates hypersensitivity to metals as a probable culprit. The team found that in patients who experienced unexplained pain postsurgery, women were more likely than men to test positive for sensitization to the metal-containing components used in the replacement procedure. The report concludes that "These findings may explain, at least in part, the sex disparity in the outcomes of certain TJA [total joint arthroplasty] implant designs." The findings were published last week in Journal of Bone & Joint Surgery.

The researchers reviewed the cases of 2,613 patients whose postsurgical joint pain could not be explained by signs of infection, inflammation, or other probable cause. Patients averaged 62 years of age, and 60% were women. On the 0 to 10 pain scale, the women reported an average score of 6.8 vs 6.1 for the men. A lymphocyte transformation test (LTT) was administered to assess hypersensitivity to cobalt, chromium, and nickel, one or more of which could be present in the implant components. Test results found immune sensitization in 49% of the women, vs 38% of the men. The authors note that their findings do not clarify whether the sensitization disparity is due to hormonal or other biologic factors, or to environmental elements such as exposure to metals in cosmetics or jewelry.